Dagger/Knife:  A small knife weapon with a flat two-edged blade measuring approximately 20 cm in length.  Daggers are usually carried in a belt sheath, and less frequently concealed in a boot sheath or strapped to the forearm.  Daggers are usually the last weapon of defense, and worn constantly.

Data Display-Recorder Headpiece:  The headset represents a significant breakthrough in display technology.  It can be interfaced with virtually any number of devices of the same or lower tech level, using a multiplexer.  The multiplexer not only coordinates the devices for the user but also synchronously records the multiple data signals onto one standard data clip for later review.

It is common for any technician using equipment to wear one of these.  Their use is also common among bridge and engineering personnel on starships as well as smaller craft.  For example, a surveyor flying in a grav belt and using a neural activity sensor can control both the sensor and his grav belt from his headpiece.  If he is also wearing a vacc suit, he can monitor and control his life-support status as well.

The headset allows the wearer to use eye motion to control the movement of device control settings.  With practice, the use of the headset to control multiple devices can become as instinctive as flipping a light switch to turn on the lights.  When desired, the headpiece can be swung up out of the weay above the head; when the display is turned off, it is transparent.

About 3 percent of the population find it difficult to focus properly on the headpiece and are unable to use the device.

Door, Wooden:  This is a sturdy door of hardwood (maple, ash, etc.) about 7.5 centimeters thick.  The door is barred on one side by a two-by-four.

Dragon's Tooth:  A dragon's tooth is a pyramid-shaped reinforced concrete obstacle one meter wide and one meter high.  Dragon's teeth are typically set in overlapping belts, with two meters between teeth and two meters between belts.  It takes 16 teeth to cover one 10-meter by 10-meter square.  Such a belt precludes movement by any ground vehicles.  Dragon's teeth and similar obstacles are often used in conjunction with anti-personnel mines.

Dynamite:  The most common explosive used by civil engineers for demolitions, it is relatively easy to manufacture and is coming into more common military use.  A quarter kilogram stick has a DP value of 1.  Dynamite is sold in cases of 100 quarter-kilo sticks.